In the field of horology, a timepiece movement inside a watch case may be provided with a striking mechanism in a conventional architecture. Such a striking mechanism generally includes a gong fixed at one of its ends to a gong-carrier, which is in turn integral with a watch plate carrying the movement, and a hammer for striking the gong at determined moments. This striking mechanism is used, in particular, for minute-repeaters or for an alarm. The gong may be a metal wire of circular shape, which may be disposed around the timepiece movement.
A conventional striking mechanism is formed of individual elements, which are intended to be assembled one after the other on the watch plate. The assembly of the striking mechanism can generally take a long time to achieve, which is a drawback. Further, the elements forming the striking mechanism have to be manufactured independently of each other. Account must also be taken of the configuration of at least one gong of the striking mechanism, which should optimise the efficiency of the watch striking mechanism to transmit vibrations more efficiently in combination with the various other elements of the watch. Improved propagation of vibrations from the gong to the external parts, such as the watch case, is desired, but difficult to achieve with a conventional striking mechanism.
EP Patent No 2 196 869 B1, which discloses a watch case with a striking mechanism, may be cited in this regard. The gong and gong-carrier of the striking mechanism are made at the same time as the middle part and/or the back cover of the watch case. The gong and gong-carrier are integral either with the middle part, or the back cover to form one piece with the middle part or the back cover of the watch case.
However, one drawback of such an embodiment is that the gong is related to the manufacture of the watch case, which is consequently complex and expensive. It is therefore not possible to select the material forming the gong without taking account of the material of the watch case. When it is desired to change the gong to modify the strike sound of the striking mechanism or due to breakage or an observed defect, one part of the watch case must also be changed, which is a drawback.